PANOSTEITIS IN PUPPY

Panosteitis in an osseous disease, also called enostosis, that mainly affects large breed puppies between 3 and 12 months old. German shepherd alone represents 75 % of cases. 2 cases out of 3 concern male puppies.

Clinical signs

Panosteitis is characterized by a sudden lameness, however difficult to localize precisely. Front legs are the most often affected, but in 50 % of cases, several limbs are concerned successively. During a crisis, the puppy is reluctant to palpation because its limbs are painful. Its internal temperature also climbs up.

The diseases evoluates during 1 to 6 months, including acute crisis during a few weeks, spaced out by periods without any clinical symptom. The evolution is generally favourable, as crisis become less and less frequent.

Complementary examination

X-rays of long bones (especially humerus), show an augmentation of the bone density in the central part of the bone, the medulla. Opaque areas appear, with no distinct limits. They can extend progressively, and fill out the most important part of the medullar cavity. The peripheric part of the bone, the cortex, is sometimes thickened, because of the reaction of the cartilage that protects the bone, the periosteum. (cf figure).

These radiographic signs become obvious 10-15 days after the beginning of the clinical signs. When panosteitis goes down, the bone lesions get progressively relieved. However, affected bones may stay slightly distorted.

Blood analysis does not reveal any biological modification, except for an anormally high percentage of some white cells, the eosinophil ones ; (usual value in dog: 2 - 6 %). Somehow, this modification is very inconstant and without any specificity towards panosteitis.

Origin ?

Various causes are evocated: allergy, infectious disease, hormonal trouble (hyperoestrogenism), stress… But the precise origin of panosteitis is not yet known. The fact that large breed male puppies are the most affected ones suggests a predisposing genetic factor.

In some blood lines of dogs suffering from a deficiency in a coagulation factor, it has been noticed that haemophilia could be associated with panosteitis.

Overfeeding (inducing an excessively fast growth), and calcium excess in puppies’ diets would be predisposing factors.

Treatment

As clinical signs progressively vanish anyway, there is no specific treatment. In severely affected puppies, anti-inflammatory drugs may be advised during crisis to limit the pain. In a long term use, these drugs induce a risk of bone demineralization, so they are contra-indicated more than 10 - 15 days. Vitamin C administration is useless.

Puppies energetic intake has to be strictly controlled, and calcium supplementation is prohibited. Affected puppies physical activity shoud be limited.

Prognosis

In most of cases, the disease spontaneously evoluates towards complete recovery, within 6 up to 18 months maximum.